Catalytic conversion of hydrocarbons



E. E. sENsEL 2,337,419 CATALYTIC CONVERSION 0F HYDROCARBONS Filed Jan. les, 19'42 2 sheets-Sheet 1 EUGENE E. SeNsEl.

Dec. 21, 1943.

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' INVENTOR A TTRNEYS Dec. 21, 1943. E. E. sENsEl.

CATALYT'IC CONVERSION OF HYDROCARBONS Filed Jan. 6, 1942 2 SheetsA-Sheet 2 COMPLEX PRDMOTER CHARGE \3 FIG.3.

QSE/Lafaille E. SENSEL.

[NI/ENTOR A TTORNE YS HIS Patented Dec. 21, 1943 CATALYTIC CONVERSION F HYDROCARBONS Eugene E. Sensel, Beacon, N. Y., assigner to The Texas Company,l New York, N. Y., a corporation of Delaware Application January s, 1.942,v serial No. 425,735

` 4 claims. (ci. 26o-7683.5)

This invention relates to the conversion of hydrocarbons and has to doqlwith the catalytic conversion of hydrocarbons to produce gasoline hydrocarbons of improved octane rating.` It is applicable to the isomerization of hydrocarbons and particularly low boiling hydrocarbons to form highly branched hydrocarbons.

The invention broadly contemplates a method of and apparatus for effecting conversion lof hydrocarbons by contact with a solid conversion catalyst maintained under conversion conditions such that substantial hydrocarbon conversion is secured, and provision is made for continuously removing heavy liquid reaction products from the solid catalyst substantially as rapidly as formed and therebymaterially reduce catalyst deterioration.

More specifically the invention contemplates a method of and apparatus for effecting isomerizevtion of paraiin and naphthene 'hydrocarbons wherein the hydrocarbons are subjected tocontact with a solid isomerization catalyst and provision is made for continuously removing from the catalyst mass liquid products of reaction substantially as rapidly as formed.

According to one modification, the invention inf volves passing astream of feed hydrocarbon in the vapor phase through a series of relativelyl shallow beds of solid catalyst in succession, the

catalyst being maintained under isomerizing con-` ditions'such that substantial conversion to isoparamnis secured. Provision is made for continuously withdrawing liquid material which` ac-V cumulatesin each bed.

In accordance with the invention a metallic-35 halide catalyst suchas aluminum chloride in lump or otherfragmentary form is disposed in a plurality of shallow beds supported one above the other within a reaction tower. Each bed is spaced substantially apart and traps areprovided in the spaces between succeeding beds, the traps being adapted to collect `and continuously (or'intermittently) discharge liquid drip from each catalyst bed. The feed hydrocarbon at the reaction temperature is passed in a continuous stream of-vapor through the reaction tower owing through the succeeding beds in series. The

` stream of hydrocarbons including isomerized hydrocarbons is withdrawn from` the reaction tower after passage through the finalcatalyst bed in the series. The withdrawn hydrocarbon mixture is advantageously subjected to fractionation to separate low boiling and high boilingvcontions comprising theeisomerized hydrocarbon 40. zone. A further advantage resides in thus el'- product. Unreacted hydrocarbons and gaseous' Another modication of the invention contemv plates a liquid phase operation in which the reacting lhydrocarbons are maintained in liquid phase or substantially so, provision being made for segregating liquid complex `and heavy hydrocarbon material at successive points within the reaction zo'ne and for discharging the segregated material therefrom.

'The invention is' of particular advantage with respect to the isomerization of a lowboiling hydrocarbon such as normal butane .wherein the hydrocarbon is isomerized by `contact in the vapor phase with a solid metallic halide catalyst such as aluminum chloride in the presence of a promoter such as hydrogen chloride. The catalyst tends to enter into. reaction with hydrocarbons during the conversion with the formation of hydrocarbon-metallic halide complex liquid compounds. The presence of the complex material as well as other heavy hydrocarbon reaction prod-.- v

Furthermore, the complex liquid exerts a softening effect upon the solid metallic halide so that individualV lumps orA particles ol' tne catalyst disintegrate, tending to convert the catalystinto a single solid mass comparatively l'ree from voids,

and therefore resistant to the passage or hydrocarbon vapors through it.

Accordingly, an important advantage of the invention resides in providing means ror tnecontinuous removal of liquid complex substantially as rapidly as it accumulates .within the reaction fecting removal olotner lleavy liquid hydrocar- V bons which may be produced as a result ol the 'stituents and thereby produce a fraction or iracconversion treatment. 4'l'rieI presence ol' such liquid hydrocarbons in thecatalyst mass is also undesirable since they may undergo cracking during continued contactwith the catalyst with the formation Yof secondary products, thereby increasing the extent oi catalyst deterioration.

In order to describe tlie invention, more iully reference will now be made to the accompanying Y drawings. l

Referring to Fig. 1 of the drawings a feedhy- Y* drocarbon such as normal butane is conducted from a source not shown through a pipe land'y ducing the heated feed'hydrocarbon-to disposed of in any Suitable manner assed through a heater;v wherein it is heatedo go a temperature in the range about 180 to 240 and referably about 200 to 220 F..

Thre heated hydrocarbon is conducted from the providing means for intro- :a reaction tower at a plurality of successive points as indicated'. JAS illustrated the tower is arranged o downward flow of hydrocarbon vapor. f r feed may be introduced to the top now downwardly all ofthe hydrocarbon charge thus..l

If desired all of the of the tower therethrough, being forced to lyst-bed. y

The numeral 6 designates a plurahty of catalyst beds, comprising aluminum chloride in lump form and these beds are ofl relatively shallow depth trays1. Thus each bed may be about 5 to 6 feet'in depth or in the range from abouti to 1,0 feet. l i y The trays 1 are provided with a large number of perforations or ports, through flow. Trays of the bubble cap type and caused to flow through each successive catarmay be employed.

Funnel shaped bafiles 8 are placed in the spacesY between each bed, each ybaille having a port at its vertex, and adapted the bed immediately above it.

Positioned a short distance below each baille 8 is a drip pan 9 adapted to receive-the liquid flowingv through the port in the vertex of the baille immediately above it. A conduit III extends from the bottom of each pan through the wall of the tower and-terminatesin afdischarge pipe II exterior of the tower.

3 communicating with Y to collect liquid drip from in this instance isobutane,

` both belowand above butane.

the vertical wall' of the tower 5 both below and above each baille 8, and conduits provided exterior the tower connecting the ports above and below each baille so as to pass the vapors around each or any baille.

Returning to Fig. 1, the hydrocarbon vapors after passage through the nal .catalyst bed, namely, the lowermost bed, shown in the tower of the drawings, are discharged through a pipe I3 leading to a fractionator I4. y'The hydrocarbons passing Vto the fractionator III will comprise normal butane and a small amount of hydrocarbon material boiling In addition it will comprise a small amount of promoter, namely,

` hydrogen chloride.

which fluid may Y to permit "separation of Il is advantageously such as the reacted hydrocarbon mixture into a plurality of fractions. Thus, a fraction consisting essentially of lgaseous constituents including hydrogen chloride promoter The fractionator may be removed through a pipe I5 and recycled allor in part through a pipe I6 to the reaction i tower.

Thus, during operation .liquid hydrocarbons A and complex liquid compounds Vaccumulatingon the catalyst lumps dripVv from the bottom oreach bed into the funnel baiiies from there into the pans 9 from which the liq- 8 below each bed and uid material isV continuously drained o through Y the conduits into the discharge pipe II. liquidrnay be conducted from the discharge pipe II toI a receiving ,tank I2. The iiquidand complex material collecting in Athetanlr I2 maybe wherein the hydrocarbons and catalyst maybe recovered for further disposition; Y f l Y Although not shown, liquid seals or other means may be vprovided in the conduits I0 for thepurpose of preventing the escape of hydrocarbon vapors through the conduits.

provided between the fun--A Sufficient space is nel battles 8 and the adjacent pans 9 andthe diameter of the ports in the bales'is suiciently largeso as to permit hydrocarbon vapor to'pass from a preceding without substantial interference with the ,flow of liquid downwardlyv through the baflles.

If desired separate ports or conduits may be provided for the passage of vapors throughfor around the funnel bailles 8. Thus, as' shown lin YFig. 2 the ports in the .vertices of -thebailles may be made integral with the corresponding conduits I0. Risers 3U are providedin each baille, each riser being surmounted by a`suitable cap 3I to prevent liquid dropping downwardly through the riser while permitting ow of vapor yeither upwardly or downwardly through the riser depending upon the direction of vaporffl'ow through the reaction tower.

' Instead of provid'ingrisers 30 through the ballles Bas shown in Fig. 2 f ports may be'provided in tofa succeeding catalyst bedV 'of isobutane may through a pipe I'I while a An intermediate fraction consisting essentially be removed as a side stream fraction consisting essentially of unreacted hydrocarbon, for normalbutane maybe drawn oilv through pipe Il and` recycled to the reaction zone. Higher molecular weight'materialmay be removed from the fractionator through apipe I9.

The fraction removed the pipe I1 may comprise some unreacted normal butane.

isobutane as well as However, any

suitable provision may be made for effecting sep` aration between Visorrierizedv hydrocarbons and unreacted hydrocarbons so that the unreacted hydrocarbons such asr normal butane may be recycled to the reaction tower.

r'The catalytic reaction in the reaction tower 5 is promoted with a hydrogen halide such as hydrogen chloride, hydrogen bromide, or with any other suitable promoting or activating Vsubstance such as carbon Vtetrachloride and low molecular weight alkyl chlorides capable of providing hydrogen halide in the reaction. A small amount of'prornoter substance is advantageously added continuously from a source/not shown through regulate the a pipe 20. It may be injected into the heated feed hydrocarbon passingy through the pipe-3. If desired the'promotermay be introduced directly to the reaction tower at aplurality of successive poirits as indicated.

Reference has already been made tothe provisionfor injection of the feed hydrocarbon at a pluralityl of successive points. This is advantageous particularly where it is5desired to temperature of the succeeding catalyst beds. In such case a suitable proportion .of the cold hydrocarbon feed vapor may be bypassed aroundthe heater 2 and'injected directly y to the reaction tower at a plurality of intermediate points.

Other means for controlling the temperature vof the catalyst bedl may be employed as, for example, cooling coils imbedded within the catalyst mass and through which coils a heat exchange medium may be circulated.

kSince the catalyst undergoes some deterioration due to complex formation and a resulting complex liquid is continuously removed the quantity of solid catalyst will'progressively diminish.

` Therefore, provision maybe made for the continuous introduction of solid catalyst to the reexample,

as a side'stream through l able screw conveyors not shown, and adapted to force the solid catalyst into each bed through manholes or ports 2|. Similar conveyors may be employed for continuous withdrawal of partly used catalysts While a specific type of trapping means has been described above with which to collect and remove the liquid Vdrip from each catalyst bed, nevertheless it is 'contemplated that other forms of trapping means may be employed 'for the purpose of collecting and discharging therliquid substantially as rapidly as it accumulates in the successive stages within the reaction tower.

Fig. 3 of the drawings illustrates a reaction tower provided with a different arrangement for collecting and discharging liquid complex materialk therefrom.

As in the case of the tower illustratedin Fig. 1 Y

a plurality of beds 6 of isomerization catalyst is provided. In' the space between each bed is placed a funnel-shaped baffle 40 having a port at its vertex and adapted to collect liquid drip from the bed immediately above it. The peripheral edge of each baille makes direct contact with the adjacent inner surface of the wall of the tower so as to provide a fluid-tight contact.

The port in the vertex of each baille communicates with a discharge pipe 4| extending through the Ywall of the tower.

The discharge pipes 4| communicate with a common pipe 42 through which the liquid material drawn off from each pan is conducted from the system.

As in the case of the tower in Fig. 1 the charge and promoter may be introduced from a pipe 3 through a charge manifold 4 providing means for introducing the heated feed hydrocarbon to the tower at a plurality of successive points. In each case the point of feed introduction to the tower may be just below each succeeding catalyst bed so as to provide upward flow of feed hydrocarbon through the catalyst masses.

According to one method of operation, parallel i'low of feed hydrocarbons through the several catalyst beds may be employed. In such operation the treated hydrocarbons are removed from a point above each catalyst bed. Discharge pipes 43 are provided for this purpose and these pipes communicate with a common pipe 44 through which the treated hydrocarbons are conducted to the fractionator.

When the successive beds are operated with series flow the stream of hydrocarbonsv issuing from above each bed is conducted through the pipes 43-as before into the pipe 44 but returned through branch pipes 45 providing inlets to the tower at points just below each catalyst bed. In this manner the pipes 43 and 45 provide means for conducting the upilowing hydrocarbons around each baffle 40.

Suitable valves as indicated may be provided in the pipe 44 and the pipes 43 and 45 for the purpose of controlling'the flow of fluid therethrough.

With the valve means thus provided it is also possible to bypass one or more of the catalyst beds.

The reaction tower illustrated in Fig. 3 also lends itself to the possibility of operating in the liquid phase. The pans 4U may be positioned Vso as to permit sufficient settling space within which to effect stratification between liquid reacting hydrocarbons and liquid complexY Y material.

Floats or other indicating means may be provided in each settling space with which to control the interface level within each settling`space. Also with liquid phase operation, either upward or downward flow of Vfeed hydrocarbons maybe employed. n Y f While a single reaction tower has been described it is also contemplated that a plurality of reaction towers maybe employed. Moreover, itis also contemplated that-a system may be used involving a plurality of individual reaction vessels keach containing an individual and relatively shallow bedof catalyst, provision being made for trapping out liquid `ijiccumulating in the bottom of each stage or vesseLthe vapors substantially free from liquid passing into a succeeding stage.

Mention hasxbeen made of employingf the invention in the isomerization of normal butano. However, it is contemplated that the invention may lbe employed for effecting isomerization of other hydrocarbons such as gasoline and naphtha hydrocarbons or fractions thereof.

It is also contemplated that the isomcrization reaction may be carried out in the presence of an agent adaptedlto inhibit or substantially reduce cra'ckingor other side reactions/which otherwise tend to'occur when subjectingT feed hydrocarbons to contact with` an isomcrization' catalyst. Such agents may` include gaseous agents such as carbon monoxide, hydrogen and hydrogen-containingV gases such as methane, ethane, etc. Normally liquid agents may be employed such as naphthene hydrocarbons. `Also mixtures of gaseous and liquid agents may be employed with provision for separating such agents from the products removed from the rcaction zone and recycling them thereto.

In carrying out the isomerization reaction provision may be made for removing oleinic and aromatic hydrocarbons, sulfur compounds and other impurities which tend to poison a metallic halide isomerization catalyst.

While aluminum chloride has been specifically the` standpoint of faciltating washing of the solid catalyst in situ with a suitable wash solvent adaptedcto remove complex and heavy liquid materlal adhering to the catalyst. For example, the catalyst mass may be washed periodically with solvent such astetrachloroethane, chlorcbenzene, orthodichlorobenzene and methylene dichloride.

Obviously many modifications and variations of the invention as above set forth may be made without departingfrom the spirit and scope thereof, and therefore, only such limitations should be imposed as are indicated by the appended claims.

I claim:

1. A method of isomerizing contact with a solid metallic halide isomerization catalyst which comprises disposing a plurality of shallow porous beds/oi solid metallic halide within a reaction tower, each bed being spaced vertically apart, with a partition between beds to provide substantial settling space below ydrocarbon in liquid phase through the beds in :series flow such that feed hydrocarbons are isom- Yerized, the conversion being accompanied by forhydrocarbons by t 4 Y Y l mation of liquidcomprising Ymetallic lhalide-hydrocarbon complex, maintaining a body of hydrocarbons and said complex in each settling space,-

s somerized hydrocarbons after passage from the effecting stratification of ,liquid thereinV to form a hydrocarbon -phase and a complex phase, with- Y drawing the separated complex lfrom the reaction tower, thev hydrocarbon phase remaining for fur- Yther contact with the catalyst; passing reacted V and unreacted hydrocarbons from apreceding stage to a; succeeding istage, and continuouslyfV removing somerized hydrocarbons after'passage f from the final bed. f

2. A method of 'isomer'izing hydrocarbons by contact with solidrgmetallic halide isomerization Y catalyst which comprises disposing a plurality of shallow porous beds of A:solid aluminum chloride within a reaction tower, 'each bed being spaced vertically apart, with a partition between beds to provide substantial vsettling'space below each bed, maintaining said catalyst beds under condinal'bed.

3. The methodaccording to` claim 2 in which the feed hydrocarbon consists essentially of nor- Y mal butane and the isomerization reaction kis effected at a temperature in the range'about 200 to 220 F. Y x 1 Y 4. Amethod of isomerizing hydrocarbons by contact with a lsolidY metallic halide isomerization .catalyst which'comprisesdisposing a plurality of shallow porous beds of solid metallic halide -within .a lreactiontower, leach bed being spaced vertically apart, with a Partition between beds to provide substantial settling space belowl each bed,rmaintaining said catalyst beds under conditions such that` isomerization constitutes Y the principal reactioncontinuously introducing tions suchthat Visomerization constitutes the principal Ireaetion,k continuously passing feed hyfeed hydrocarbons in liquid phase to said tower, maintaining a body of liquidghydrocarbons undergoing treatment moving vupwardly throughy each catalyst bed in series, said hydrocarbons undergoing isomerization during contact with the catalystfsaidV conversion being accompaniedby drocarbon in liquidphase through the bedsl inVVV series fiowin -thepresence of hydrogen halide such that feed hydrocarbons are isomerized, the conversion being accompanied `by formation of `liquid comprising metallic halide-hydrocarbon complex, maintaining4 a body of hydrocarbons' and said complex in each settling space, effecting startiflcation-of liquid ,thereinV to form a hydrocarbon phase and a complex phase, withdrawing the separated 'complex from thereaction tower, Y the hydrocarbon `phaseremaining for further I contact with the catalyst, passingreacted and unreacted hydrocarbons from a1 preceding stage to a succeeding stage, and continuously removing' formation of liquid comprising metallic halidehydrocarbon complex, effecting stratification of Vliquid inthesettling space below each bed to form a hydrocarbon phase and a complex phase, withdrawing said complex phase from the reaction tower, the hydrocarbon phase remaining as a component of said body of hydrocarbons rising through the catalyst beds, ,conducting hydrocarbon liquid after passage through a preceding bed t to the space below the succeeding bed, and removing isomerzed hydrocarbons after passage from 'the final bed. f i

' EUGENE E. SENSELl 

